Mountain Equipment Helium 600 Sleeping Bag (-10°C/14°F)

Filled with 620g of ethically sourced duck down boasting a minimum 700-fill power and encased in a robust yet featherweight 100% recycled Helium 20D outer fabric, the Helium 600 offers exceptional warmth, minimal weight, and remarkable compressibility for effortless stowing. It is built to endure, making it an excellent choice for early spring or autumn adventures in higher altitudes or colder northern climates.

Its slant-baffle construction runs through the body, expertly retaining heat, enhancing compressibility, and preventing the down from shifting—ensuring warmth without compromise and eliminating cold spots. The footbox features a Trapezium four-baffle layout that wraps heat securely around the feet, while a five-baffle hood construction delivers targeted insulation and keeps the fill exactly where it’s needed.

Inside, the sleeping bag is lined with 100% recycled Supersoft 20D fabric, treated with a PFAS-free durable water repellent for breathable comfort and dependable longevity. A full-length Gemini™ zip baffle significantly reduces heat loss in this vulnerable area, with added stiffening to avoid snagging. The streamlined Lode Lock™ magnetic closure and intuitive collar drawcords are designed for ease of use, even in low-light conditions.

Constructed with the Alpine 2.0 fit, this bag balances a technical profile with comfort, maximising thermal efficiency while keeping weight to a minimum. With a Good Night’s Sleep Temperature of -10°C (14°F), the Helium 600 consistently delivers warmth across cool-weather excursions in spring and autumn or at elevated locations.

Features

Insulation

• Each baffle is individually optimised to provide the best possible warmth-to-weight ratio.
• The regular size contains 620g of 90/10 duck down with a fill power exceeding 700.
• The long version holds 651g of 90/10 duck down with 700+ fill power.
• All down is ethically sourced via DOWN CODEX© and certified under RDS 3.0 standards.
• Every bag is tagged with a unique DOWN CODEX© code for complete transparency on sourcing and performance.

Materials

• The HELIUM™ 20D fabric is a lightweight (38gsm), 20-denier recycled textile designed to strike the ideal balance between resilience, compressibility, and protection from the elements. It is tightly woven to prevent wind penetration and heat loss, finished with a PFAS-free DWR coating.
• The Supersoft™ lining features a 38gsm, 20D recycled downproof nylon construction, offering breathability, lasting durability, and a soft touch against the skin. It also benefits from a PFAS-free DWR treatment.

Patterning & Design

• The sleeping bag has been engineered for both durability and performance over prolonged use.
• The Women’s Alpine Fit has a tapered silhouette and incorporates the zoned EXL® system, which increases thermal efficiency while trimming down the weight.
• Slanted box-wall baffles help cut down on structural bulk while ensuring optimal insulation.
• Strategic placement of the down fill—especially in high-compression areas like the underside, hood, and foot box—helps retain warmth and prevents the fill from shifting.

Foot box

• The Trapezium 4 System uses a four-baffle arrangement to retain warmth and avoid compression in the foot area, keeping toes toasty.

Hood

• The hood’s five-baffle construction allows precise control of the down fill, offering outstanding insulation without adding unnecessary weight.
• Its design is spacious yet cosy, with dual tether drawcords to help seal in the warmth.

Zip Baffles & Collars

• The Gemini™ Baffle System is a streamlined, lightweight construction that reduces heat escape while maintaining full zip protection.
• The Lode Lock™ System uses a magnetic fastener with a mechanical lock for one-handed, quick-release functionality.
• The down-filled, adjustable neck collar is integrated for an added layer of insulation.

Additional Features

• A waterproof roll-top stuff sack is included to optimise pack space and keep contents dry on the move.
• A storage cube is provided to preserve the loft of the down, enhancing long-term performance and ideal for storing the bag at home.
  
  

Specifcations

Technology

	Down 700 Down is the finest insulator that we have. Its warmth to weight ratio, compressibility, long lifespan, and softness are yet to be matched by manmade insulations. For all but the most serious expeditions, duck down is a great choice for both insulated clothing and equipment.
	Helium Helium fabrics are exceptionally light, compressible and soft. Their densely woven construction ensures the highest levels of down-proofing and wind resistance.
	Down Codex® The DOWN CODEX® is our multi-award-winning certification scheme that considers the environmental, ethical and animal welfare matters relating to our down supply chains. It is grounded in comprehensive and transparent auditing that ensures traceability and quality.
	Fair Wear As a member of Fair Wear, Mountain Equipment is committed to implementing the highest standards of working conditions. Mountain Equipment were awarded 'Leader Status' by Fair Wear Foundation in 2016 and has been awarded their highest accolade for performance every year since.

Detail Shots

	Using slanted box-wall baffles throughout the entire main body of the helium bags means weight is removed from the bags structure, yet they remain a significant step above a standard box baffle.
	5 baffle anatomically shaped hood.
	4 baffle anatomically shaped and offset foot-box.
	Full length Gemini zip baffle with 140cm zip and integrated neck collar with Lode Lock closure.
	100% recycled HELIUM 20D outer shell is very light and highly breathable with PFC free DWR.
	Integrated neck collar with Lode Lock closure.

More Information

Helium Sleeping Bags

Efficiently sized, supremely comfortable and low in weight each Helium bag offers outstanding all-round performance for backpackers, cycle-tourers and trekkers. These bags don’t skimp on features and will keep you warm and comfortable whether on a summer road-trip or extended trek.

Shop The Helium Range

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